C is a general purpose programming language. Originally intended for implementing system software, C and its close relatives are the principle languages used in most modern operating systems. Due to its thin layer of abstraction and low overhead, C allows efficient coding of algorithms and data ...
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0answers
38 views
over fitting avoidance
I distributed my data into 90% training and 10% testing, then I build a boosting regression model using GBM boosting package in R which is very similar to the famous Adaboost regression model. There ...
1
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2answers
94 views
What sparse solver supports diagonal storage format
I'm writing finite-difference method program using C. The stiffness matrix is symmetrical and band. For its storage I'd like to use Sparse Diagonal Storage format.
Could someone tell please, what ...
5
votes
5answers
184 views
Evaluate the sum
I want to evaluate the sum $$\sum_{k=1}^\infty \left(\frac{i+1}{\sqrt{2}}\right)^k\cdot k^{-\alpha}$$ where $i=\sqrt{-1}$ and $\alpha\in[\frac{3}{4},1]$ with 8 digits accuracy.
If I am willing to ...
3
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2answers
85 views
Are matlab C library versions backwards compatible?
I have some C++ code that links to matlab2008b. Are matlab 2012a and 2012b backwards compatible with 2008b?
If it's not trivially compatible, are there some simple steps to make it compatible?
7
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3answers
280 views
Recommendations for a lightweight/no-install C or C++ based dense linear algebra solver
Most of my programming is one-off research codes in C for my own use. I have never distributed any code to other than close collaborators. I have developed an algorithm that I am publishing in a ...
4
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2answers
234 views
Extracting a 2D matrix from a multidimensional array in C
In my c language program, I have to store multiple dense $m\times m$ matrices corresponding to gridpoints $x_i$ with $i=1,...,n$. I decided to create a three dimensional array $A\in R^{n\times ...
5
votes
1answer
209 views
Open-source, thread-safe implementation of convex optimization solvers in C/C++?
Is there an open-source, thread-safe implementation of convex optimization solvers in C/C++?
Some libraries such as NLopt, Ipopt, OPT++ don't meet my requirements.
OPT++ and Ipopt aren't ...
5
votes
3answers
277 views
How do I know if my code is being vectorized by the compiler?
As exemplified by Jed Brown's answer to Costs of lookups versus calculations, using vectorized vs non-vectorized floating point operations results in much faster code. Many modern compilers claim ...
11
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4answers
805 views
Is C slower than Fortran on the spectral norm shootout (using gcc, intel and other compilers)?
The conclusion here:
How much better are Fortran compilers really?
is that gfortran and gcc are as fast for simple code. So I wanted try something more complicated. I took the spectral norm shootout ...
2
votes
1answer
88 views
Implicitly casting PetscReal to the real part of PetscComplex
The version of Petsc installed on my machine has PetscScalar set to be complex. I am making a matrix which has all real entries.
Something like the following code compiles:
...
12
votes
3answers
705 views
I/O Strategies for computational problems with large data sets?
My research group focuses on molecular dynamics, which obviously can generate gigabytes of data as part of a single trajectory which must then be analyzed.
Several of the problems we're concerned ...
9
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0answers
145 views
Is there a tool out there that can generate interval extensions of Fortran (or C) functions by parsing Fortran (or C) code?
Case studies in my PhD thesis require that I have interval extensions of Fortran subroutines in CHEMKIN-II (apologies for the link; it's the best one I could find for a package no longer distributed ...
2
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3answers
268 views
How to obtain finite difference, which is continuous
I want to calculate a finite difference (something like this SO Post). My data is as follows: I have x-values that are powers of two (4, 8, 16, 32 and 64). Corresponding to them are y-values, such ...
29
votes
4answers
3k views
How much better are Fortran compilers really?
This question is an extension of two discussions that came up recently in the replies to "C++ vs Fortran for HPC". And it is a bit more of a challenge than a question...
One of the most often-heard ...
4
votes
1answer
314 views
Which libraries have good implementations of Basis splines?
I'm looking to use the finite element method with B-splines as my function basis. Which C/C++ libraries have good B-spline support?
Specifically, I'm looking for an implementation of a stable ...
3
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1answer
227 views
PETSc's makefile system can't find MKL
I'm learning PETSc and trying to make the examples written in C. However, when I use the provided makefile, I get the following error:
...
33
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14answers
1k views
Is it common not to use libraries for standard numerical algorithms, and why?
A lot of numerical algorithms (integration, differentiation, interpolation, special functions, etc.) are available in scientific computation libraries like GSL. But I often see code with "hand-rolled" ...
7
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2answers
400 views
Is there an open source set of ODE solvers for C that use the native C99 complex type?
I've been using GSL as the foundation of many of my simulations, but it's a little bit overkill for my purposes and it defines its own complex type for legacy reasons. Rather than code my own ...
13
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8answers
553 views
Parsing protein structure data in C
My background is in genomics, but I have recently been working with problems related to protein structure. I wrote a few relevant programs in C, building my own PDB file parser from scratch in the ...
